Heel gripping device for ski bindings

ABSTRACT

A heel gripping device for a ski binding comprises a housing attachable to the ski and carrying a slidable element which is urged forwardly by a spring to project from the housing and engage a groove in the heel of the ski boot to hold the same against the ski in a downhill skiing configuration. A rotatable cam is mounted in the housing and is turned by an external actuating handle to retract the slidable element and permit the boot to be lifted in cross-country skiing.

United States Patent Labor et a1.

[451 Aug. 21, 1973 I-IEEL GRIPPING DEVICE FOR SKI BINDINGS Inventors: Kurt Labor; Dietrich Grunau, both of Markdorf; Gustav Tarant, Beuerberg, all of Germany Assignec: Peter Muller, Oy, Germany Filed: Jan; 31, 1972 Appl. No.: 222,133

Foreign Application Priority Data Jan. 29, 1971 Germany P 21 04 167.8

US. Cl 280/l1.35 T

Int. Cl. A63c 9/00 Field of Search 280/1 1.35 T

References Cited UNITED STATES PATENTS 5/1957 Braun 280/1 1.35 T

Frisch 280/1 1.35 T

Unger 280/11.35 T

9 Primary Examiner-Benjamin Hersh Assistant Examiner-Robert R. Song Attorney-Eric H. Waters, John G. Schwartz et a1.

A heel gripping device for a ski binding comprises a housing attachable to the ski and carrying a slidable element which is urged forwardly by a spring to project from the housing and engage a groove in the heel of the ski boot to hold the same against the ski in a downhill skiing configuration. A rotatable cam is mounted in the housing and is turned by an external actuating handle to retract the slidable element and permit the boot to be lifted in cross-country skiing.

ABSTRACT 10 Claims, 3 Drawing Figures Patented Aug. 21, 1973 3 Sheets-Sheet 1 Patented Aug. 21, 1973 3,753,572

3 Sheets-Sheet 2 Pat ented Aug. 21, 1973 3,753,572

3 Sheets-Shoot 3 FIG. 3

BACKGROUND OF THE INVENTION 1. Field of the Invention The invention relates to heel gripping devices for ski bindings.

2. Prior Art There are known heel gripping devices which disengage for safety purposes when the forces exerted upon them exceed a pre-determined value. Such gripping devices incorporate a plurality of elements and they are expensive to manufacture.

SUMMARY OF THE INVENTION It is an object of the invention to provide a heel gripping device which is composed of just a few elements which can be manufactured inexpensively and whose operation is not impaired by corrosion.

It is another object of the invention to provide a heel gripping device which can easily be converted from a downhill binding gripping configuration to a crosscountry binding gripping configuration, the heel of the ski boot in the latter configuration being capable of being lifted from the surface of the ski without losing lateral stability.

The invention contemplates a heel gripping device for ski bindings comprising a housing which can be attached to the ski, a sliding member which is supported in the housing for slidable movement in a direction generally longitudinally of the ski, said sliding member projecting from an opening provided in the front portion of the housing when in the gripping position and being held in this position by means of a spring. An eccentric cam is rotatably supported in the housing by means of an axle extending transversely to the longitudinal direction of the ski, said eccentric cam being connected to an actuating handle which is arranged outside of the housing. The cam is provided with at least two surface portions, one of which has a smaller, and the other a larger, distance from the axis of rotation of the eccentric cam, the latter portion being in contact with the sliding member in its open position in which the ski boot can be inserted into the binding, and in which position the front portion of the sliding member is retracted into the housing against the action of the spring.

According to one of the features of the invention, the actuating handle is constructed as a guiding device with a concave curvature, when observed from the front, for travel of a sliding element which can be engaged with the ski boot. The actuating handle is able to assume a position in which it is directed upwardly and slightly forwardly, in which position, a third portion ofthe surface of the eccentric cam engages the sliding member, said third portion having such a large radial distance from the axis of rotation of the eccentric cam that the front portion of the sliding member does not substantially project from the housing whereby a universal binding is constructed in a simple manner which is equally suitable for down-hill skiing and for crosscountry skiing.

BRIEF DESCRIPTION OF THE DRAWING FIG. 1 is a vertical cross-section through the gripping device in a heel gripping position for downhill skiing,

FIG. 2 is a substantially horizontal cross-section of the gripping device in the heel gripping position for downhill skiing, and

FIG. 3 is a side elevation view similar to FIG. 1, wherein, however, an actuating handle and the gripping device are in position for cross-country skiing.

DETAILED DESCRIPTION Referring to the drawing, the gripping device comprises a one-piece housing 11 made of synthetic resinous material such as nylon or the like, the housing being provided with a continuous longitudinal bore having an axis 12 which is slightly inclined toward the front and downwardly. The bore consists of three portions 13, 14 and 15 whose cross-sections increase stepwise from front to rear, said cross-sections preferably being circular and serving for guiding a sliding member 16. An insert 18 is engaged in the rear portion 15 of the bore, and secured therein by means of two screws 19. The insert 18 is provided with an inner thread 20 into which a bolt 21 is threadably engaged, the front end of bolt 21 engaging a spring 22 whose other end presses against the front surface of a coaxial blind hole in the sliding member 16. The depth of threaded engagement of the threaded bolt 21 in the insert determines the resistance to disengagement of the gripping device and the depth can be read from a scale indicator 23 on bolt 21. A jam nut 24 secures the bolt in its pre-determined position.

The housing 11 is provided with two lateral recesses 25 bounded by opposed vertical guiding surfaces 26 and an upper surface 27. A fitting plate 28 is inserted from below into each of the recesses and defines an inner chamber therewith. Each plate 28 is provided with a transverse bore 29. An eccentric cam 31 is disposed in each inner chamber, said eccentric cam being made of a one-piece body of synthetic resinous material with a bearing journal 30 rotatably supported in the bore 29. The axes of rotation 46 of the bearing journals 30 are aligned transversely with respect to the central vertical plane of the housing 11. A U-shaped actuating handle 33 has an end inserted in a radial hole 32 in each of the journals 30, and the end is secured in hole 32 by means of a securing pin 34.

The actuating handle 33 has two parallel arms, each with a middle portion 36 which is of concave curvature when viewed from the front (from the left in the drawing).

A sliding element 37 is mounted on the handle 33, the element 37 being provided with lateral grooves 40 slidably receiving portions 36 of the arms of the actuating handle 33.

The sliding element 37 has two front tongues 39 which hold the sliding element against the ski boot at 38 when the actuating handle 33 is in the position for cross-country skiing as illustrated in FIG. 3. Therein the center of curvature of the guiding portion 36 is located approximately at the surface of the ski 35 and its distance from the guiding portion 36 is approximately equal to the length of the sole of the ski boot.

The housing 11 is provided with front and rear bottom flanges which are provided with bores 42, through which screws 43 extend in order to attach the housing to the ski. At the rear surface of the sole of the ski boot, there is provided a concave groove 44 (or there is mounted a corresponding fitting provided with a concave groove) into which the front, convex end 45 of the sliding member 19 is pressed in the gripping position of FIG. 1. The groove 44 has a larger width as compared to its height, so that, consequently, the vertical curvature is larger than the horizontal curvature. As a result, disengagement is assured in such a manner that a larger force is needed for disengagement in the case of a frontal fall than in the cases of diagonal or rotational falls.

The cam 31 is approximately circular and has a geometric mid-point 47 which is spaced from its axis of rotation 46. As a result, the portion of the circumference of the eccentric cam 31 with the largest eccentricity is located in the immediate prolongation of a connecting line drawn through axes 46, 47 toward the right and upwardly (FIG. 3). This portion of the surface is designated as 48. In FIG. 3, a portion of the surface 49 with a slightly smaller distance to the axis of rotation adjoins portion 48 in the clockwise direction for a purpose to be explained later. The portion 49 of the surface of the eccentric cam is flattened. In FIG. 3, the portions 49 of both eccentric earns 31 engage an annular shoulder 17 of the sliding member 16. As can be seen in FIG. 2, the width of the annular shoulder 17 of the sliding member 16 corresponds to the width of the eccentric cams 31. The portion 49 of the eccentric cams 31 holds the sliding member 16 in a position in which it is retracted in the housing 1 1 (FIG. 3). The ski boot, whose front end is held in position by means of a front clamp (not illustrated) consequently, can tilt upwardly about this front clamp (as shown in FIG. 3 in chain dotted lines), whereby the sliding element 37 is displaced to the position 37'. The ski boot is laterally guided and supported when the ski boot is lifted from the surface of ski 35, by means of the sliding element 37 which slides along the guiding portions 36 of the actuating handle 33. If the radius of curvature of the guiding portion 36 is not exactly equal to the length of the sole of the ski boot, the actuating handle 33 will swivel slightly in the course of upward and downward movement of the ski boot.

The actuating handle 33 cannot freely rotate in the clockwise direction from the position in FIG. 3, as in such case the portion 48 of the eccentric cam with the largest eccentricity would come into contact with the annular shoulder 17 of the sliding member 16. The spring 22 resists undesirable backward movement of the guiding member 33 based on the different eccentricity of the portions 48 and 49 of the surface of the eccentric cam, the actuating handle thus being securely held in the position as shown in FIG. 3. Additionally, this position of handle 33 for cross-country skiing can be locked by means of a pin inserted in transverse bores 51 in the housing.

In order to convert the heel gripping device from its cross-country skiing position in FIG. 3 to its position for downhill racing (FIG. I), the actuating handle 33 is forceably rotated in the clockwise direction, whereby the spring 22 is first slightly compressed, whereafter it is almost entirely freed of stress as a result of decreasing eccentricity of the surface of the eccentric earns 31, whereby the sliding member 16 moves forwardly under the thrust of spring 22. The actuating handle is moved clockwise until it abuts against the upper surface of the ski 35. The portions 50 of the surfaces of the eccentric cams 31 which now face the annular shoulders 17 of the sliding member 16 either touchthe said annular shoulders slightly or are out of contact therewith, whereby the forward position of the sliding member 16 is only limited by the abutment of the front end 45 in the groove 44 in the ski boot and by the clamping of the ski boot in the front clamp (downhill racing position). The angle between the portion 48 of the eccentric cam surface with the largest eccentricity and the portion 50 with the smaller eccentricity is approximately If the actuating handle is rotated in the counterclockwise direction upwardly to an approximately vertical position, the portions 48 of the eccentric cams with the largest eccentricity come into engagement with the annular shoulders 17 of the sliding member, so that the sliding member 16 is retracted into the housing to its maximum extent for permitting insertion of the ski boot into the binding. If the handle 33 is moved further to a position slightly inclined toward the front from the vertical (FIG. 3), and if it is ensured that the sliding element 37 is engaged with the ski boot in the region between the heel and the sole, the heel gripping member is in its cross-country skiing position.

The heel gripping device is composed of a small number of uncomplicated structural elements, all of which with the exception of the conventional helical springs, can be made of synthetic resinous materials. The gripping device can be manufactured inexpensively and it also does not require servicing during operation, and moreover it makes possible an exactly pre-determined setting of the force for disengagement for safety reasons in the downhill racing position. Also, it can easily be converted for use as a cross-country ski binding by actuating only the single actuating handle, in which position the ski boot receives excellent lateral guidance.

What is claimed is: I

l. A heel gripping device for ski bindings, said device comprising a housing which can be attached to a ski, a sliding member mounted in the housing for sliding movement in a generally longitudinal direction, said sliding member including a front projection which extends from the housing to engage a groove in the rear portion of the heel of a ski boot when in gripping position for downhill skiing, spring means acting on the sliding member to urge the same to said gripping position, rotatable means supported in the housing for rotation about a transverse axis for moving the sliding member rearwardly against the opposition of the spring means to retract the front projection, an actuating handle extending outside the housing and engaged with said rotatable means to rotate the same, said actuating handle having a lowered position in which the rotatable means is released from the sliding member to permit the projection to extend from the housing under the action of the spring means in a heel gripping position for downhill skiing, said actuating handle being raisable to an elevated position in which said rotatable means moves the sliding member to retract the same into the housing in a cross-country skiing position; and sliding means on said actuating handle for holding the heel of the boot on the ski and for sliding on said actuating handle as the boot is lifted to guide said boot relative to said handle.

2. A heel gripping device as claimed in claim 1 wherein said actuating handle, when observed from the front, includes a curved portion which is of concave curvature, a sliding element being slidably mounted on said curved portion and engageable with the upper surface of the heel of the ski boot, said actuating handle having an upwardly and slightly forwardly inclined position in the cross-country skiing position.

3. A heel gripping device for ski bindings, said device comprising a housing which can be attached to a ski, a sliding member mounted in the housing for sliding movement in a generally longitudinal direction, said sliding member including a front projection which extends from the housing to engage a groove in the rear portion of the heel of a ski boot when in gripping position for downhill skiing, spring means acting on the sliding member to urge the same to said gripping position, eccentric cam means supported in the housing for rotation about a transverse axis for moving the sliding member rearwardly to retract the front projection, an actuating handle extending outside the housing and engaged with said cam means to rotate the same, said cam means including at least two surface portions, one of which has a greater radial distance to the axis of rotation of the cam means, the latter cam portion being in contact with the sliding member in its retracted position to enable the ski boot to be inserted into the binding, said sliding member being retracted against the opposition of the spring means, said housing being provided with two inwardly open, and mutually opposite, lateral recesses, each with a transversebore, the transverse bores being coaxially aligned, said cam means comprising an eccentric cam in each recess, said sliding member including a shoulder portion in each recess, said eccentric cam means including a cylindrical journal rotatably supported in each transverse bore and laterally projecting from the housing, the actuating handle comprising a two armed member having ends attached to respective journals.

4. A heel gripping device as claimed in claim 3, wherein said housing is formed as a one-piece body provided with two lateral openings, and a plate dismountably inserted into each opening, to define said inner recess.

5. A heel gripping device as claimed in claim 3, wherein said actuating handle has a lowered position in which the cam means is released from the sliding member to permit the projecting portion to extend from the housing under the action of the spring means in a heel gripping position for downhill skiing, said actuating handle being raisable to an elevated position in which said one surface portion engages the sliding member to retract the same into the housing in a cross-country skiing position; and sliding means on said actuating handle for holding the heel of the boot on the ski and for sliding on said actuating handle as the boot is lifted to guide said boot relative to said handle.

6. A heel gripping device as claimed in claim 5, wherein the cam means has a third surface portion engaging the sliding member in the elevated position of the actuating handle, said third portion being at a radial distance from the axis of rotation of the eccentric cam means that the front projection of the sliding member is substantially retracted into the housing. 1

7. A heel gripping device as claimed in claim 6, wherein said third surface portion has a slightly smaller radial distance from the axis of rotation of the eccentric cam means than said one surface portion.

8. A heel gripping device as claimed in claim 7, wherein said third surface portion is flattened.

9. A heel gripping device as claimed in claim 3, wherein at least said housing is made of a synthetic resinous material.

10. A heel gripping device as claimed in claim 3, wherein the actuating handle, when observed from the front, includes a curved portion which is of concave curvature, a sliding element being slidably mounted on said curved portion and engageable with the heel of the ski boot, and wherein the center of curvature of the curved portion is located approximately at the surface of the ski and its distance from said curved portion is approximately equal to the length of the sole of the ski boot. 

1. A heel gripping device for ski bindings, said device comprising a housing which can be attached to a ski, a sliding member mounted in the housing for sliding movement in a generally longitudinal direction, said sliding member including a front projection which extends from the housing to engage a groove in the rear portion of the heel of a ski boot when in gripping position for downhill skiing, spring means acting on the sliding member to urge the same to said gripping position, rotatable means supported in the housing for rotation about a transverse axis for moving the sliding member rearwardly against the opposition of the spring means to retract the front projection, an actuating handle extending outside the housing and engaged with said rotatable means to rotate the same, said actuating handle having a lowered position in which the rotatable means is released from the sliding member to permit the projection to extend from the housing under the action of the spring means in a heel gripping position for downhill skiing, said actuating handle being raisable to an elevated position in which said rotatable means moves the sliding member to retract the same into the housing in a cross-country skiing position; and sliding means on said actuating handle for holding the heel of the boot on the ski and for sliding on said actuating handle as the boot is lifted to guide said boot relative to said handle.
 2. A heel gripping device as claimed in claim 1 wherein said actuating handle, when observed from the front, includes a curved portion which is of concave curvature, a sliding element being slidably mounted on said curved portion and engageable with the upper surface of the heel of the ski boot, said actuating handle having an upwardly and slightly forwardly inclined position in the cross-country skiing position.
 3. A heel gripping device for ski bindings, said device comprising a housing which can be attached to a ski, a sliding member mounted in the housing for sliding movement in a generally longitudinal direction, said sliding member including a front projection which extends from the housing to engage a groove in the rear portion of the heel of a ski boot when in gripping position for downhill skiing, spring means acting on the sliding member to urge the same to said gripping position, eccentric cam means supported in the housing for rotation about a transverse axis for moving the sliding member rearwardly to retract the front projection, an actuating handle extending outside the housing and engaged with said cam means to rotate the same, said cam means including at least two surface portions, one of which has a greater radial distance to the axis of rotation of the cam means, the latter cam portion being in contact with the sliding member in its retracted position to enable the ski boot to be inserted into the binding, said sliding member being retracted against the opposition of the spring means, said housing being provided with two inwardly open, and mutually opposite, lateral recesses, each with a transverse bore, the transverse bores being coaxially aligned, said cam means comprising an eccentric cam in each recess, said sliding member including a shoulder portion in each recess, said eccentric cAm means including a cylindrical journal rotatably supported in each transverse bore and laterally projecting from the housing, the actuating handle comprising a two armed member having ends attached to respective journals.
 4. A heel gripping device as claimed in claim 3, wherein said housing is formed as a one-piece body provided with two lateral openings, and a plate dismountably inserted into each opening, to define said inner recess.
 5. A heel gripping device as claimed in claim 3, wherein said actuating handle has a lowered position in which the cam means is released from the sliding member to permit the projecting portion to extend from the housing under the action of the spring means in a heel gripping position for downhill skiing, said actuating handle being raisable to an elevated position in which said one surface portion engages the sliding member to retract the same into the housing in a cross-country skiing position; and sliding means on said actuating handle for holding the heel of the boot on the ski and for sliding on said actuating handle as the boot is lifted to guide said boot relative to said handle.
 6. A heel gripping device as claimed in claim 5, wherein the cam means has a third surface portion engaging the sliding member in the elevated position of the actuating handle, said third portion being at a radial distance from the axis of rotation of the eccentric cam means that the front projection of the sliding member is substantially retracted into the housing.
 7. A heel gripping device as claimed in claim 6, wherein said third surface portion has a slightly smaller radial distance from the axis of rotation of the eccentric cam means than said one surface portion.
 8. A heel gripping device as claimed in claim 7, wherein said third surface portion is flattened.
 9. A heel gripping device as claimed in claim 3, wherein at least said housing is made of a synthetic resinous material.
 10. A heel gripping device as claimed in claim 3, wherein the actuating handle, when observed from the front, includes a curved portion which is of concave curvature, a sliding element being slidably mounted on said curved portion and engageable with the heel of the ski boot, and wherein the center of curvature of the curved portion is located approximately at the surface of the ski and its distance from said curved portion is approximately equal to the length of the sole of the ski boot. 